In the 1960s, Armacost taught international relations and foreign policy at Pomona College.[2]
Armacost was a White House Fellow in 1969-1970. Founded in 1964, the White House Fellowship is one of America’s most prestigious programs for leadership and public service. The Fellowship, awarded on a strictly non-partisan basis, offers exceptional young leaders first-hand experience working at the highest levels of federal government.
Armacost served as Acting Secretary of State from January 20, 1989, to January 25, 1989. Between 1995 and 2002, he served as president of the Brookings Institution.
Armacost has received the President's Distinguished Service Award, the Defense Department's Distinguished Civilian Service Award, and the Secretary of State's Distinguished Services Award.
Armacost is the author of three books, the most recent of which, Friends or Rivals?, was published in 1996 and draws on his tenure as ambassador. He also co-edited, with Daniel Okimoto, The Future of America's Alliances in Northeast Asia, published in 2004 by Stanford Walter H. Shorenstein Asia-Pacific Research Center.[4] Armacost has served on numerous corporate and nonprofit boards, including TRW, AFLAC, Applied Materials, USEC, Inc., Cargill, Inc, Carleton College, and The Asia Foundation.
Armacost is a Fellow of the National Academy of Public Administration.[citation needed] He was chairman of Carleton College's board of trustees from 2004 to 2008.[7]